An organic electroluminescence (EL) device is considered to be a promising inexpensive large full-color display that utilizes solid-state emission, and has been extensively developed. The organic EL device normally includes an emitting layer, and a pair of opposing electrodes that are disposed on either side of the emitting layer. When an electric field is applied between the electrodes, electrons are injected from the cathode, and holes are injected from the anode. The electrons and the holes recombine in the emitting layer to produce an excited state, and the energy is emitted as light when the excited state returns to the ground state.
A known organic EL device has problems in that a high driving voltage is required, and only low luminance and low luminous (emission) efficiency can be achieved. It is important to improve the luminous efficiency of an organic EL device in order to reduce the power consumption of a display, and the materials used to produce an organic EL device have been gradually improved in recent years (see Patent Documents 1 and 2, for example). However, a further improvement in efficiency has been desired.